噻虫嗪对螺旋粉虱的室内毒力与田间药效

Toxicity and field efficacy of thiamethoxam to Aleurodicus disperses

以螺旋粉虱为试虫，在室内用叶面喷雾、包柄和浸液法，田间用喷雾、包茎和灌根法，对噻虫嗪杀虫效果进行了评价。结果表明，室内毒力中，药后144h3种方法处理对螺旋粉虱若虫的校正死亡率均达到70％以上，且正面喷雾效果略好于浸液法和包柄法。药剂对螺旋粉虱成虫同样具有较高的活性。在田间的药效评估中，药后144h，500mg／L的高浓度处理校正虫口减退率均达到73．00％以上，且叶面喷雾的速效性明显高于灌根和涂茎。其中药后24h的喷雾与灌根和涂茎的效果差距在1～2倍之间，药后120h灌根和涂茎也分别表现出74．55％和73．66％的良好效果。且从药后72h虫口回升情况来看，体现了噻虫嗪具有较强的内吸传导性和持效作用。上述结果表明，噻虫嗪的内吸传导作用最强，其次为触杀活性，并有一定的渗透性，在田间持效期长，在生产中可以根据需要选择使用不同的施药方式和适合的有效剂量以达到最佳防治效果。

Aleurodicus disperses Russell is a new invasive dangerous pest in Hainan Province, and it causes serious harm. The activity of thiamethoxam to A. disperses was comprehensively evaluated at 5 different concentrations and by 3 treatment methods. The results showed that the corrected whitefly nymph mortality rates reached 70% in all 3 treatments in 144 h. To assess the efficacy in field experiments, the corrected decrease rate of insect populations reached more than 73.00% at the concentration of 500 mg/L in 144 h, and the efficacy by spraying was significantly higher than that by stem-packaging and root-treating. These results provided useful information for whitefly control by using thiamethoxam.